#define _CRT_SECURE_NO_WARNINGS 1
#include<stdio.h>
int main()
{
	int a, b, c;
	scanf("%d %d %d", &a, &b, &c);
	if ((a <( b + c)) && (b <( a + c)) && (c <(a + b)))
	{
		if (a == b && a == c && b == c)
		{
			printf("Equilateral triangle!");
		}
		else if ((a == b) || (b == c) || (a == c))
		{
			printf("Isosceles triangle!");
		}
		else
			printf("Ordinary triangle!");
	}
	else
		printf("Not a triangle!");
	return 0;
}